The oxygen evolution reaction (OER) is known as the efficiency-limiting step for the electrochemical cleavage of water mainly due to the large overpotentials commonly used materials on the anode side cause. Since Ni-Fe oxides reduce overpotentials occurring in the OER dramatically they are regarded as anode materials of choice for the electrocatalytically driven water-splitting reaction. We herewith show that a straightforward surface modification carried out with AISI 304, a general purpose austenitic stainless steel, very likely, based upon a dissolution mechanism, to result in the formation of an ultra-thin layer consisting of Ni, Fe oxide with a purity > 99%. The Ni enriched thin layer firmly attached to the steel substrate is responsible for the unusual highly efficient anodic conversion of water into oxygen as demonstrated by the low overpotential of 212 mV at 12 mA/cm 2 current density in 1 M KOH, 269.2 mV at 10 mA/cm 2 current density in 0.1 M KOH respectively. The Ni, Fe-oxide layer formed on the steel creates a stable outer sphere, and the surface oxidized steel samples proved to be inert against longer operating times (> 150 ks) in alkaline medium. In addition Faradaic efficiency measurements performed through chronopotentiometry revealed a charge to oxygen

Iodine (I) biofortification of vegetables by means of soil and foliar applications was investigated in field experiments on a sandy loam soil. Supply of iodine to the soil in trial plots fertilized with potassium iodide (KI) and potassium iodate directly before planting (0, 1.0, 2.5, 7.5, and 15 kg I ha-1) increased the iodine concentration in the edible plant parts. The highest iodine accumulation levels were observed in the first growing season: In butterhead lettuce and kohlrabi the desired iodine content [50–100 μg I (100 g FM)-1] was obtained or exceeded at a fertilizer rate of 7.5 kg IO3--I ha-1 without a significant yield reduction or impairment of the marketable quality. In contrast, supplying KI at the same rate resulted in a much lower iodine enrichment and clearly visible growth impairment. Soil applied iodine was phytoavailable only for a short period of time as indicated by a rapid decline of CaCl2-extractable iodine in the top soil. Consequently, long-term effects of a one-time iodine soil fertilization could not be observed. A comparison between the soil and the foliar fertilization revealed a better performance of iodine applied aerially to butterhead lettuce, which reached the desired iodine accumulation in edible plant parts at a fertilizer rate of 0.5 kg I--I ha-1. In contrast, the iodine content in the tuber of sprayed kohlrabi remained far below the targeted range. The results indicate that a sufficient spreading of iodine applied on the edible plant parts is crucial for the efficiency of the foliar approach and leafy vegetables are the more suitable target crops. The low iodine doses needed as well as the easy and inexpensive application may favor the implementation of foliar sprays as the preferred iodine biofortification strategy in practice.

In spite of the drastic oil price collapse in the second half of 2014 resulting in a price below 30 $/barrel in January 2016 1 , the exploration of promising renewable energy sources for the Abstract: Water splitting allows the storage of solar energy into chemical bonds (H 2 +O 2 ) and will help to implement the urgently needed replacement of limited available fossil fuels. Particularly in neutral environment electrochemically initiated water splitting suffers from low efficiency due to high overpotentials (η) caused by the anode. Electro-activation of X20CoCrWMo10-9, a Co-based tool steel resulted in a new composite material (X20CoCrWMo10-9//Co 3 O 4 ) that catalyzes the anode half-cell reaction of water electrolysis with a so far-, unequalled effectiveness. The current density achieved with this new anode in pH 7 corrected 0.1 M phosphate buffer is over a wide range of η around 10 times higher compared to recently developed, up-to-date electrocatalysts and represents the benchmark performance advanced catalysts show in regimes that support water splitting significantly better than pH 7 medium. X20CoCrWMo10-9//Co 3 O 4 exhibited electrocatalyticproperties not only at pH 7, but also at pH 13, which is much superior to the ones of IrO 2 -RuO 2 , single-phase Co 3 O 4 -or Fe/Ni-based catalysts. Both XPS and FT-IR experiments unmasked Co 3 O 4 as the dominating compound on the surface of the X20CoCrWMo10-9//Co 3 O 4 composite. Upon a comprehensive dual beam FIB-SEM (focused ion beam-scanning electron microscopy) study we could show that the new composite does not exhibit a classical substrate-layer structure due to the intrinsic formation of the Co-enriched outer zone. This structural particularity is basically responsible for the outstanding electrocatalytic OER performance.2 future is one of the significant challenges for scientists and engineers concerned with energy issues research. Splitting of water into hydrogen and oxygen by exploiting solar energy transforms water to an inexhaustible and environmental friendly fuel source 2,3,4,5,6,7,8,9 .Electrocatalytically initiated hydrogen-and oxygen formation from water is considered an important realization of this solar to fuel conversion route 10,11,12 but is typically hampered by the high overpotentials oxygen evolution on the anode side goes with 13,14 . This is particularly true when the electrochemical cleavage of more or less untreated water is intended-; hence, when the splitting procedure is carried out at neutral pH value. 17,18,19,20,21,22,23,24 . Scheme 1 gives some idea of the position of current heterogeneous catalysts in terms of their efficiency regarding OER in neutral regime. The significant improvement of the voltage-current behavior can be taken from both-, the non-steady state ( Figure 1a) as well as the steady state polarization (Figure 1b) experiments. Results OER properties in neutral mediumThe CV of sample Co-300 shows along the entire curve substantially stronger current to voltage ratio than the CV of sample Co and reached, at the upper...

Biofortified apples seem to be a suitable produce. In this study, different selenium forms and application levels were applied to the two apple varieties ‘Golden Delicious’ and ‘Jonagold’, grown in the years 2017 and 2018 in order to increase the selenium uptake within a typical Western diet. It was shown that the biofortification, which was performed as a foliar application implemented in usual calcium fertilization, led to significantly increased selenium contents in the fruits. Furthermore, biofortification affected the total phenolic content (TPC), the polyphenol oxidase activity (PPO), as well as the antioxidant activity (AOA), the latter measured with the two well-known assays Trolox Equivalent Antioxidant Capacity Assay (TEAC) and Oxygen Radical Absorbance Capacity Assays (ORAC). The varying selenium forms and application levels showed a differing influence on the parameters mentioned before. Higher fertilizer levels resulted in higher selenium accumulation. It was found that PPO activity fluctuates less in biofortified apples. With regard to TPC, selenate led to higher amounts when compared to the untreated controls and selenite resulted in lower TPC. AOA analysis showed no clear tendencies as a result of the selenium biofortification. In the case of ‘Jonagold’, a higher AOA was generally measured when being biofortified, whereas, in the case of ‘Golden Delicious’, only one form of application led to higher AOA. Additionally, differences in the amount of major phenolic compounds, measured with High Performance Liquid Chromatography Mass Spectrometry (HPLC-DAD-ESI-MSn), were observed, depending on the conditions of the biofortification and the variety.

The present study investigates consumers’ acceptance of Se-biofortified apples, as well as Se health and nutrition claims that have been approved by the European Commission. Despite indications that such statements are more likely to be accepted if the carrier product itself has a healthy image, unprocessed fruits biofortified with Se have not been investigated in this context yet. Apples as the most frequently-consumed type of fresh fruit in Germany may offer the potential to improve the Se status of consumers when the produce is enriched with Se. Therefore, an online survey of 356 German adults was conducted to analyze different aspects that could affect the perception of and preference for the proposed product concept by consumers. The findings indicate a moderate acceptance of Se-biofortified apples, as well as of Se health and nutrition claims among the participants. Additional information about beneficial health effects of Se had a significant impact on consumer acceptance. People who regularly eat convenience food and prefer to buy apples at supermarkets were particularly attracted by the product idea. In conclusion, the results of the study indicate good prospects for a successful introduction of Se-rich apples in the German food market, if the produce is advertised with approved health and nutrition claims.

The use of proton exchange membrane (PEM) electrolyzers is the method of choice for the conversion of solar energy when frequently occurring changes of the current load are an issue. However, this technique requires electrolytes with low pH. All oxygen evolving electrodes working durably and actively in acids contain IrOx. Due to their scarcity and high acquisition costs, noble elements like Pt, Ru and Ir need to be replaced by earth abundant elements. We have evaluated a cobalt containing steel for use as an oxygen-forming electrode in H2SO4. We found that the dissolving of ingredients out of the steel electrode at oxi-dative potential in sulfuric acid, which is a well-known, serious issue, can be substantially reduced when the steel is electro-oxidized in LiOH prior to electrocatalysis. Under optimized synthesis conditions a cobalt-containing tool steel was rendered into a durable oxygen evolution reaction (OER) electrocatalyst (weight loss: 39 µg mm −2 after 50 000 s of chronopotentiometry at pH 1) that exhibits overpotentials down to 574 mV at 10 mA cm −2 current density at pH 1. Focused ion beam SEM (FIB-SEM) was success-fully used to create a structure-stability relationship.

Many people across the world suffer from iodine (I) deficiency and related diseases. The I content in plant-based foods is particularly low, but can be enhanced by agronomic biofortification. Therefore, in this study two field experiments were conducted under orchard conditions to assess the potential of I biofortification of apples and pears by foliar fertilization. Fruit trees were sprayed at various times during the growing season with solutions containing I in different concentrations and forms. In addition, tests were carried out to establish whether the effect of I sprays can be improved by co-application of potassium nitrate (KNO3) and sodium selenate (Na2SeO4). Iodine accumulation in apple and pear fruits was dose-dependent, with a stronger response to potassium iodide (KI) than potassium iodate (KIO3). In freshly harvested apple and pear fruits, 51% and 75% of the biofortified iodine was localized in the fruit peel, respectively. The remaining I was translocated into the fruit flesh, with a maximum of 3% reaching the core. Washing apples and pears with running deionized water reduced their I content by 14%. To achieve the targeted accumulation level of 50–100 μg I per 100 g fresh mass in washed and unpeeled fruits, foliar fertilization of 1.5 kg I per hectare and meter canopy height was required when KIO3 was applied. The addition of KNO3 and Na2SeO4 to I-containing spray solutions did not affect the I content in fruits. However, the application of KNO3 increased the total soluble solids content of the fruits by up to 1.0 °Brix compared to the control, and Na2SeO4 in the spray solution increased the fruit selenium (Se) content. Iodine sprays caused leaf necrosis, but without affecting the development and marketing quality of the fruits. Even after three months of cold storage, no adverse effects of I fertilization on general fruit characteristics were observed, however, I content of apples decreased by 20%.

2High overpotentials, particularly an issue of common anode materials, hamper the process of water electrolysis for clean energy generation. Thanks to immense research efforts up to date oxygen evolution electrocatalysts based on earth-abundant elements work efficiently and stably in neutral and alkaline regimes. However, non-noble metal-based anode materials that can withstand low pH regimes are considered to be an indispensable prerequisite for the water splitting to succeed in the future.All oxygen evolving electrodes working durably and actively in acids contain Ir at least as an additive. Due to its scarcity and high acquisition costs noble elements like Pt, Ru and Ir need to be replaced by earth abundant elements. We have evaluated a Ni containing stainless steel for use as an oxygen-forming electrode in diluted H 2 SO 4 . Unmodified Ni42 steel showed a significant weight loss after long term OER polarization experiments. Moreover, a substantial loss of the OER performance of the untreated steel specimen seen in linear sweep voltammetry measurements turned out to be a serious issue. However, upon anodization in LiOH, Ni42 alloy was rendered in OER electrocatalysts that exhibit under optimized synthesis conditions stable overpotentials down to 445 mV for 10 mA cm -2 current density at pH 0. Even more important: The resulting material has proven to be robust upon long-term usage (weight loss: 20 µg/mm 2 after 50 ks of chronopotentiometry at pH 1) towards OER in H 2 SO 4 . Our results suggest that electrochemical oxidation of Ni42 steel in LiOH (sample Ni42Li205) results in the formation of a metal oxide containing outer zone that supports solution route-based oxygen evolution in acidic regime accompanied by a good stability of the catalyst.3